Just yesterday I was praising Tim Noakes’ The Lore of Running to a friend who recently started training to run his first marathon. Then this morning over breakfast I stumbled across a fascinating article in the March 20 New Scientist (paper only, not the web) about new research Noakes and colleague Alan St. Clair Gibson have been doing on the nature of physical exhaustion in endurance athletes. They think it’s all in our brain, acting as a sort of “central governor” to get our body to slow down well before we actually reach the point of physical exhaustion, essentially leaving us with enough in reserve to flee if there happens to be a lion around the next corner. One can see how that would have been an evolutionary advantage back in the day.
Noakes is this strange and wonderful South African ultra-distance runner and exercise physiologist. The Lore of Running is one of my all-time favorite books, though an odd choice for the list. I love it because (much like another favorite, Norman Maclean’s Young Men and Fire) it is a work of great personal passion in which one can easily see the seams and stitches used to pull the passion together into a book. Those seams, imperfections in the book’s assembly, make it far more interesting.
Noakes’ careful obsession is with finding the science underlying the lore that has built up over the years among coaches and athletes about what works and what doesn’t. That’s what led him to the central governor theory – an anomaly that the science couldn’t quite explain. As Rick Lovett explains in New Scientist:
Timothy Noakes will never foreget the day he encountered the hill from hell. It was 1976 and he was running the gruelling Comrades Marathon, an annual 90-kilometre road race between Durban and Pietermaritzburg in South Africa. About 20 kilometres from home he rounded a bend and saw a steep incline he hadn’t known was there. Even before he started climbing, he suddenly began to feel overwhelmingly tired.
The conventional wisdom, Lovett explains, is that fatigue is a creature of the muscles themselves. But Noakes’ new research suggests that it’s the brain, taking cues from the muscles well before they are actually fatigued and giving us that exhausted shutdown signal early enough that we don’t kill ourselves, and that we don’t leave our muscles with too little in reserve to get away from the lion if need be.
This hypothesis explains a lot. The governor lets up, for example, when you know you’re nearing the finish line of a race. The success of interval training is explained by the brain learning better where the actual point of physical exhaustion lies. By regularly pushing up near it, your brain is quickly trained to have a better idea of where the boundary actually might lie. Noakes’ tests on a group of cyclists, as explained by Lovett, found the performance improvement from interval training came much too quickly to be explained by a physiological change. And the coach’s lore that one should always know the course of a race – that’s brain, not body.
My copy of The Lore of Running is old. Guess it’s time to go out and buy the latest edition, which talks about the central governor theory.
I just want to take this opportunity to say that I, as a regular (obsessive?) Planet Gnome reader, do find your posts to be a lot of fun to read, precisely because many of them aren’t about Gnome (but are from the pen of a talented reporter). They broaden my horizons; thank you.
As a sort-of neuroscientist, I do question the face validity of the effect you describe above. Without having done any formal studies (so don’t go citing me on this!), I suspect that this effect, while quite real, is due to a conservative estimate of the point of injury for various tissues (muscle groups), rather than a desire to maintain energy reserves.